Shock wave lithotripsy (SWL) is the first line treatment for the majority of patients with kidney stones. The gold standard in SWL is still considered to be the Dornier HM3, which was the first lithotripter introduced into the US. The HM3 is an electrohydraulic lithotripter (EHL) that uses a single underwater "sparker" as a shock wave source. The HM3 has the drawback that the electrodes erode quickly and must be replaced in the middle of a procedure, and causes significant side effects. This project is to demonstrate that an array of several sparkers in small ellipsoidal reflectors can break stones without having to stop a procedure. The relatively low electrical current in each sparker in the array reduces the erosion, which may allow the sparker array to operate for multiple treatments. The flexibility in placement of the sparkers allows space for an in-line ultrasound probe to monitor stone location during treatment, which will result in fewer pressure pulses missing the stone and reduce damage to surrounding tissue. The specific project objectives are to develop a sparker array and demonstrate its efficacy by breaking artificial stones without having to replace electrodes. A successful Phase I will lead to a Phase II to develop a prototype and demonstrate the potential for improved clinical outcomes. PUBLIC HEALTH RELEVANCE: This research can lead to improved treatment of kidney stones. A successful new lithotripter will have both a higher percentage of successes (reducing the number of repeat procedures) and less side effects to the patient.